340 



A. W. BELLAMY. 



in water, about 80 per cent, of the eggs were beginning equatorial 

 gastrulation. After 20 hours in this solution and 22 hours in 

 water, about 70 per cent, of the eggs showed various stages of 

 equatorial gastrulation; the rest of the eggs varied from nearly 

 normal yolk plug stages to those showing flat-crescent blastopores 

 (Fig. 17). After 76 hours in water following 20 hours' exposure 



i nv. 2 



FIG. 18. Secondary invagination following 48 hours' exposure to m/io LiCl, 

 from an unsegmented stage. A, surface view; B, sagittal section of same egg. 

 inn. 2, secondary invagination; d.l., dorsal lip; bp. blastopore; s.c., segmentation 

 cavity. (Exp. LiCl i d.) 



to the solution about 5 per cent, of the eggs showed a secondary 

 invagination apical to the equatorial blastopore. This secondary 

 invagination appeared more prominently (in about 40 per cent, 

 to 50 per cent.) after 28 hours in w/8-5 LiCl and 48 hours in 

 water (Fig. 18). 



Experiment IV 22. 48 hours' exposure to m/ 10.62 LiCl gave 

 90 per cent, equatorial gastrulae (Fig. 19), which when returned to 

 water proceeded to develop farther and after 28 hours were in 

 elongated neural fold stages with large protruding yolk plugs. 

 After 72 hours in water following 48 hours' exposure to the solu- 

 tion one finds all stages from a few equatorial gastrula^ to micro- 

 cephalic and anencephalic forms with partially or completely 

 "fused" suckers, nasal pits, and optic vesicles. After 76 hours' 

 exposure to the solution and 20 hours in water the abnormalities 

 were more extreme. In about 5 per cent, of these the pigmented 

 cells grew out from one to ten mm. to form a cone of cells radially 

 symmetrical about the original polar axis of the egg, there being 



